This invention relates to fiber optics technology. More particularly, it relates to the provision of plug and receptacle connections for joining two fiber optics cables for optical energy transmission, and to the provision of a closure wall or door for a socket opening in the receptacle through which the plug moves when it is being connected to and disconnected from the receptacle, and to a construction of the closure wall that results in it being held both open and closed without the use of a separate coil spring.
It is common to join the ends of two fiber optics cables by the use of a connection composed of a plug at an end of one of the cables and a plug receiving receptacle at an end of the other cable. The receptacle includes a base and a plug receiving socket extending axially from the base. An end portion of a first cable is secured to the base with the end of its optic fiber directed axially of the socket. An end portion of the second or other cable is secured to the plug with the end of its optic fiber also directed axially. When the plug is inserted into the socket, the ends of the two optic fibers are moved together, to form a light energy transmitting coupling of each to the other.
It is known to provide the socket with a closure wall or door at its end through which the plug enters and leaves the socket. Prior art closure walls are hinge connected to the socket by the use of pivot pins carried by the closure wall and pivot pin receiving openings carried by the socket. A torsion spring of helical coil form is provided for biasing the closure wall into its closed position. One end of the torsion spring is anchored on the socket and the other end is anchored on the closure wall. When the closure wall is moved from its closed position to its open position, energy is stored in the coil spring. When the moving force is removed from the closure wall, this stored energy acts to move the closure wall back into its closed position and hold it there.
The use of a torsion spring adds to the manufacturing cost of the connection. There is a desire to reduce manufacturing costs. There is also a desire to provide a connection in which the closure wall is biased open and well as closed. A primary object of the present invention is to satisfy both of these desires.
An aspect of the present invention is to provide an improved receptacle component of a connection for two optical fiber cables that also includes a plug that is received in the receptacle. The receptacle comprises four sidewalls together forming a plug receiving socket having an open end through which a plug enters and leaves the socket. The four sidewalls include first and second opposite sidewalls, third and fourth opposite sidewalls that are perpendicular to the first and second sidewalls, and end surfaces on said sidewalls at the open end of the socket. The fourth sidewall has an outer surface. The first and second sidewalls include coaxial, pivot pin receiving openings that extend through them near their end surfaces, and near the fourth sidewall. The pivot pin receiving openings have axes that are spaced inwardly from the end surfaces of the first and second sidewalls the distance x and are spaced inwardly of the outer surface of the fourth sidewall a distance y. The end surface on the fourth sidewall intersects the outer surface of the fourth sidewall along an intersecting line L that is parallel to the axes of the pivot pin receiving openings. The line L is spaced from the axes of the pivot pin receiving openings a distance z that is greater than the distance x and greater than the distance of y. A closure wall is provided for the open end of the socket. The closure wall includes a pair of pivot pin support arms projecting from it and laterally inwardly projecting pivot pins on the support arms. The pivot pins are sized and positioned to be received within the pivot pin receiving openings. The support arms are of a length that places the pivot pin axes away from the inner surface of the closure wall a distance that is substantially equal to or greater than the distance x, and substantially equal to or greater than the distance y, and smaller than the distance z. When in its closed position, the closure wall extends across the open end of the socket and its inner surface substantially contacts the end surfaces of at least two of the sidewalls. When the closure wall is in its open position, its inside surface substantially contacts the outer surface of the fourth sidewall. The support arms for the pivot pins are mounted to allow movement of the closure member from its open position to its closed position and from its closed position to its open position.
According to an aspect of the invention, the closure wall includes a central portion and opposite side portion that are separated from the central portion by parallel splits that are also parallel to the first and second sidewalls. The splits have open ends that are adjacent the end surface of the third sidewall when the closure wall is in its closed position. The splits also have closed ends that are adjacent the end surface of the fourth sidewall when the closure wall is in its closed position. The support arms for the pivot pins are connected to the side portions of the closure wall adjacent the open ends of the splits, laterally outwardly of the splits. As a result, rotation of the closure wall between its open and closed positions will cause flexing of the central portion of the closure wall relative to the side portions, so as to allow the closure wall to slide over and around the intersection line L as the closure wall is moved from one of its positions to the other.
Preferably, the end surfaces of the four sidewalls substantially lie in a common end plane that is perpendicular to the outer surface of the fourth sidewall. Preferably also, the closure wall is constructed such that when it is in its open position it extends at an angle to said end plane that is greater than ninety degrees. The closure wall contacts the end surfaces of at least two of the sidewalls when the closure wall is in its closed position. This contact and the length of the support arms holds the closure wall in its closed position whereat it will stay until forcibly swung from its closed position to its open position. When the closure wall is in its open position, its inside surface substantially contacts the outer surface of the fourth sidewall. This contact and the length of the support arms holds the closure wall in its open position whereat it will stay until forcibly swung from its open position to its closed position.
In preferred form, the receptacle includes a base from which the plug receiving socket extends. The base supports an end portion of a first fiber optic cable, with its optic fiber directed axially of the socket. According to an aspect of the invention, an inside portion of the closure wall is provided with an array of reflecting surfaces that are positioned to reflect substantially obliquely outwardly, any light energy that may be omitted from the first optical cable towards the closure wall when the closure wall is closed, so that said light energy will not be reflected back on itself.
Preferably, the closure wall is constructed from a structural plastic material, facilitating its manufacture and also facilitating the flexing of the central portion of the closure wall that must occur when the closure wall is moved from its open position to its closed position and from its closed position to its open position. Plastic materials that may be suitable to provide reduced manufacturing costs, and the desired amount of flexing, may want to transmit light energy that might be directed on it. A further aspect of the invention is to provide the closure wall with a light blocking material on its outer surface, adapted to substantially prevent light energy from being transmitted through the closure wall.
Other objects, advantages and features of the invention will become apparent from the description of the best mode set forth below, from the drawings, from the claims and from the principles that are embodied in the specific structures that are illustrated and described.